Scientists ponder sun's next move from quiet phase

Could a cooler sun, which some solar astronomers now predict, save us from global warming?

The short answer is "no," scientists say.

"That would be convenient and would make a lot of people happy," said Greg Kopp, a physicist with the Laboratory for Atmospheric and Space Physics at the University of Colorado.

Kopp notes that the sun has been in a quiet phase during the last decade's rise in global temperatures.

"Human-caused climate effects are far outweighing the solar effects currently," said Kopp, who is an instrument scientist for a NASA satellite that measures the sun's heat output, or total solar irradiance.

Satellites have measured the sun's radiation at the point where it reaches Earth's atmosphere for 32 years. The average difference between energy at the peak and minimum of solar cycles is less than 0.1 percent.

That flux is easily absorbed and balanced by the Earth's oceans, Kopp said, and has a minimal effect on the Earth's temperature.